Abstract: An instrument for stapling body tissue including a staple, a retainer, and a plunger. The staple is preformed in a closed state and is made of a body-compatible material. The staple material has a stress plateau such that the staple may be flexed to an open state without permanent deformation. The retainer stores the staple in the open state and the plunger ejects the staple from the retainer such that the staple returns itself to the preformed closed state in the body tissue.

Abstract: Apparatus for rotating an annular or ring shape tool such as a saw blade or grinding wheel. The tool is rotated by a power driven drive roller acting on a face of the ting tool. A rigid arm supports guide rollers which in turn support the tool. The guide rollers have grooves that engage the inner periphery of the ring tool. The inner periphery of the ring tool may define a tapered tongue with a rounded edge that fits into complimentary shaped grooves in the guide rollers. Fixed and movable U-shape guards are provided to shield substantially all of the ring tool.